McQuay TGZ 040A

18 TGZ 040A through TGZ 190A OMM TGZ-1
Start-Up and Shutdown
Pre Start-up
1. With main disconnect open, check all electrical connections in control panel and starter to be sure
they are tight and provide good electrical contact. Although connections are tightened at the factory,
they can have loosened enough in shipment to cause a malfunction.
2. Check and inspect all water piping. Make sure flow direction is correct and piping is made to
correct connection on evaporator and condenser.
3. Open all water flow valves to the condenser and evaporator.
4. Flush the cooling tower (if one is in the system) and system piping to be sure the system is clean.
Start source water pump and manually start hot water pump. Check all piping for leaks. Vent the air
from the evaporator and condenser water circuit as well as from the entire water system. The cooler
circuits should contain clean, non-corrosive water.
5. Check to see that the water temperature thermostat sensor is installed in the correct water line.
6. Making sure control stop switch S1 is open (off) and pumpdown switches PS1 and PS2 are on
“manual pumpdown”, move the main power and control disconnect switches to “on.” This will
energize crankcase heaters. Wait a minimum of 12 hours before starting up unit.
7. Check compressor oil level. The oil level should be at least one-third of the oil sightglass.
8. Check pressure drop across evaporator and condenser, and see that water flow is correct per the
design flow rates and data on pages 4 through 6.
9. Check the actual line voltage to the unit to make sure it is the same as called for on the compressor
nameplate within + 10% and that phase voltage unbalance does not exceed 2%. Verify that adequate
power supply and capacity is available to handle load.
10. Make sure all wiring and fuses are of the proper size. Also make sure all interlock wiring is
completed per McQuay diagrams.
11. Verify that all mechanical and electrical inspections by code authorities have been completed.
12. Make sure all auxiliary load and control equipment is operative and that an adequate cooling load is
available for initial start-up.
Start-up
1. Open the compressor suction and discharge shutoff valves until backseated. Replace valve caps.
2. Open the manual liquid line shutoff valve.
3. Check to see that the unit circuit breakers are in the “off” position.
4. Check to see that the pumpdown switches PS1 and PS2 are in the “manual pumpdown” position and
the control system switch S1 is in the “off” position.
5. Place the main power and control circuit disconnects to the “on” position.
6. Verify crankcase heaters have operated for at least 12 hours prior to start-up. Crankcase should be
warm.
7. Adjust the setpoint on the MicroTech controller to the desired hot water temperature.
8. Start the auxiliary equipment for the installation by turning on the time clock, ambient thermostat
and/or remote on/off switch and chilled water pump.
9. Check resets of all equipment protection controls.
10. Switch the unit circuit breakers to on.
11. Place pumpdown switch(es) PS1 and PS2 to “auto” for restart and normal operation.
12. Start the system by pushing the system switch S1 to on.
13. After running the unit for a short time, check the oil level in each compressor crankcase and check
for flashing in the refrigerant sightglass.
14. After system performance has stabilized, it is necessary that the “Compressorized Equipment
Warranty Form” (Form No. 206036A) be completed to obtain full warranty benefits. Be sure to list
the pressure drop across both vessels. This form is shipped with the unit and after completion
should be returned to the McQuay Service Department through your sales representative.